Cutter-grinding machine



1; 1. THACHER.

CUTTER GRINDING MACHINE.

' APPLICATION FILED OCT- 21, 1919.: I I 1,389,325. H Patented Aug. 30, 1921.

' 2 SHEETS-SHEET 1.

i I Q I mmml W I 2 6 50% ado/m 1 m 1.]. THACHER.

CUTTER GRINDING MACHINE.

I APPLICATIUN FILED OCT- 21,1919- P27 8. 2 SHEETSSHEET 2.

- in Patent 730,455 granted to Mr.

UNITED STATES PATENT OFFICE.

JOHN .T. TEACHER, or wETHERsrInLn, CONNECTICUT, ASSIGNOR To PRATT &

WHITNEY COMPANY, or NEW YORK, N. Y., A CORPORATION on NEW 7 JERSEY.

CUTTER-GRINDING MACHINE.

Specification of Letters Patent. Patented Aug. 30, 1921 Application 'filed October 21, 1919. Serial No. 332,323.

To all 10 710m it may concern Be it known that I, JOHN J. THACHER, a citizen of the United States, residing at \Vethersfield, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Cutter- Grinding Machines, of which the following is a specification.

This invention relates to cutter grinding machines and particularly to an improvement on the cutter grinding machine shown BQM. W. Hanson on June 9th, 1903.

In a grinding-machine of the type stated,

there is provided a rotatable work support and one or more spindles having grinding wheels thereon adapted to be moved across the work, such work-herein being shown as a milling cutter and the grinding wheels being shown as sharpeningthe same. Mechanism is provided between the drive shaft and the spindles for longitudinally reciprocating the latter across the work in the grinding operation. It is a particular object of this invention to provide an improved mechanism for this purpose which wlll be more rigid and less susceptible to wear and which will better sustain the main strain and wear of the machine which is required of this reciprocating mechanism.

Certain of the grinding spindles 1n the present invention are mounted on a support adjustable circumferentially about the machine frame and it is a particular object of the invention to provlde improved operating means for reciprocating these sp1ndles in whatever position the spindle supports may be adjusted. r

When operating on outters of relatively small size, the actual working stroke of the grinding spindles is shorter than when working on larger cutters and it is therefore not I necessary that the spindles operate at full stroke on such small work. It is accordingly an object of the invention to provide improved means for adjusting the stroke of the spindles to the length desired.

With the above and other objects in view, which will be more fully disclosed as the de scription of the invention proceeds, the invention more specifically resides in the fol lowing structure.

Referring to the drawing:

I Figure 1 is aplan View Of the improved cu ter grind g m chi e.-

v F 1g. 2 is apart sectional View taken approx mately on the line 22 of Fig. 1 looking in the direction of the arrow, certain elements being omitted therefrom and other parts being shown in elevation to more clearly disclose the improved structure constituting the invention.

F 1g. 3 is a sectional view taken on the line 33 of Fig. 2 looking in the direction of the arrow and showing certain parts broken away to more clearly disclose the invention.

F 1g. 4 is a detail view showing more clearly the mechanism whereby the length of stroke of the grinding spindles may be varied.

Referring more specifically to the drawing by reference characters wherein like numerals designate like parts in the several yiews, l designates a suitable pedestal servmg as a support for the bed plate 2 of the grinding machine and preferably has secured adjacent its upper end a pan 3 for conveniently holding any tools being used by the operator. As in the aforesaid patent, the work spindle support 4 is mounted directly on the bed plate 2 and held'thereon by means of screws or otherwise. The work spindle 5 is journaled in this support and adapted to be indexed by a suitable mecha nism hereinafter described.

' Two grinding spindle supports 6 are mounted on the bed plate 2 andare secured in any position circumferentially thereon by means of clamps 7 extending into the T-slot S in the bed plate. As shown most clearly in Fig. 3, a slide 9 forming at its upper end a bearing for the grinding'spindle 10 is mounted to slide transversely on each of the supports 6. A third grinding spindle 10 is mounted in a like slide 9 which is adjustably mounted directly on the bed plate 2. A screw 11 is provided as identical and from the structure just described it should be clear that two of the spindles may be adjusted in a direction transversely of the spindle itself, that each spindle is movable longitudinally in operat o a th t t o of the spindles are circhine frame.

cumferentially adjustable on the bed plate. The mechanism thus far specifically described is substantially that shown in the patent referred to above.

The improved means for operating the work performing elements of the machine will now be described. As hereinbefore stated, the greatest wear and strain on the machine is in those parts which reciprocate the grinding spindles in their working operation. It is therefore very essential that such mechanism be made very substantial and be of a very rigid and strong character. lVith this object in view, I have herein shown as one embodiment of my invention a series of members, each of a very substantial character and interengaged in such manner as to positively t *ansmit reciprocatary motion to the said spindles without e ccssive wear, without danger of breaking such members and without wasting energy through lost motion or looseness.

As such a means for transmitting reciprocatory motion to the spindles, I prefer to provide a series of lever arms having direct toothed engagement with each other as shown in Figs. 2 and 3. An arm ii is shown as having direct engagement with a collar 15 on each spindle although it is obvious that the engagement might as with a slidable carriage in which the spindle is mount ed if desired. The lower end of each arm. l-l is pivotally mounted on one end of a lever 16 pivoted at 1? and 17, the two pivots 17 corresponding to the two circumferentially adjustable spindles being on a bracket 18 secured to the spindle support 6 and the third pivot 17 being on the bed plate 52. Such pivoting of each arm on the lever 16 permits the slide 9 to be adjusted transversely while still maintaining the arm in operative engagement with the spindle. The other end of each circumferentially adjustable lever has tooth-ed engagement 19 with one arm of a member pivoted at 20 to an er:- tension of the bracket 18. A. second arm 2i projecting from the said member has toothed engagement with a circular rack 22. The other arm 16' of the lever 1.6 on the pivot 17 has toothed engagement 93 with the toothed sector of an arm or lever pivotally mount-- ed on a rock shaft mounted in the mart second arm or lever 25 is mounted on the other end of this shaft and is provided with a toothed sector for enga ing the circular rack 2 It is of course e 2 vious that other means than the toothed enrack 22 tothe spindles, but the structure shown is particularly n'eferable since the same is strong and accurate and not likely to-get out of order. Also the toothed en gagement between each arm 21 and the circular rack is :such that full operative en-.

gagement of these elements is maintained no mattein what circumii'erential position the spindle supports '5 may be adjust-st. It will be noted that there no necessity for circumferentially adjusting the spindle 10 hence the reason for mounting the operating means therefor directly on the machine frame.

As a means of reciprocating the circular rack from the main drive shaft 2?, I dis-- close the following mechanism. An eccentric pin 28 on the disk 25) secured to the end of the shaft .27 engages in a slot provided in a plate 80 secured to the upper end of a rod 3; (Fig. a). The circular rack 22 is slidably mounted on this rod and houses a ctanpression spring between the rack and a member secured to the lower end of the rod by means of nuts The spring 32 is sutliciently strong to normally hold the rack up in engagement with the plate 30 in such mann r that the rack normally moves with the rod the full stroke of the latter and carries the spindles through such stroke.

To shorten the operating stroke of the spindles when desired, 1 pr ride means acting aga' t the normal action of the spring 82 to limit the upward movement of the rack The herein described means for this purpose is best shown in F 2 and An arm or lug extends outward from the hub of arm on the rock shaft and a screw is adapted to be adjusted into the path. of movement of said lug to limit the rocking movement of the rock shaft in one direction. As shown in Fig. 2, this screw is threadedly mounted in a bracket 3'? on the machine frame and may be adjusted tnrough the bracket to any position desired to thereby limit the upward movement of rack and the operative stroke of the spindles. referring to Fig. 2 it will be seen that the red 3i always operates at the same stroke and that compre sion of spring and rmiting of the upward movement of the 'ack.

is shown in Jig. 3 I prefer to drive the main drive shaft 27 through a gear 38 and step pulle 39 on a co ntershaft i0 mounted in a ln'aclret all, such bracket serving as a belt tightener by the operation of screw elf Gear meshes with a gear i3 on the drive shaft 2? whereby the drive shaft and the machine are operated.

llLS heretoil'ore stated. the work spindle 5 is mounted on the support and is adapted to carry on one end thereof a cutter i to sharpened and on the other end a toothed index wheel 4:5. During the sharpening operation it is necessary that the cutter be roscribed. A hub L6 carrying an arm at? and :a projection 48 is loosely mounted on the lit) spindle .5 and connected with the cam engaging element A9 through the projection 48 and a link 50, a spring 51 surrounding the said hub normally holding theelement 4:9 in engagement with thecam 52 on the main drive shaft 27. A pawl 53 is pivotally mounted on the arm 47 andis adapted to engage the teeth of the index wheel 45 to rotate "the about the periphery of wheel 45 and in the path of movement of the pawl 53. This shield serves to lift the pawl from the wheel during a portion of its operative stroke if desired, thereby renderingthe pawl inoperaindexing work of different kinds and size may be more readily-and conveniently made tive at such time. 7

Different index wheels must be usedrfor and it is therefore often necessary to remove the wheel 45 and substitute another therefori In the drawing Ishow' one embodiment of simple means whereby this change than heretofore. As shown in Figs. 2 and p 3, the wheel 45 slides over the hub 55 and is held thereon by means of a thin threaded plate '56,having wrench engaging facets 57 oniits periphery. The opening in this plate w is kept well lubricated. This construction and in the index wheel isof such relative size that both may be removed directly from the shaft without removing the wing nut 58 or' any of the other parts of the machine. As shown in Figs. 1, 2 and 3, I have provided improved means whereby the machine comprises briefly an oil reservoir 59 having ducts leadlng therefrom to the 11111111 drive shaft and other operating parts. I also provide oil cups for the main bearings as shown in the drawings.

From the foregoing description the operation and the material advantages of the 1mproved structure should be obvious. By

providing a limited number of rigid and strong parts and by interconnecting such parts inthe positive manner shown, an im- 'proved machine has been provided which jWlll bev more accurate and will better with- ;stand the wear incident thereto without easy breakage of any parts thereof. Also the im- 'proved"adjustable spindle stroke provided renders the machine very accurate and the arrangement of the parts is very compact and such that the, spring 32 is completely housed. The full operative engagement bei tween the levers 21 and the circular rack 22 in all circumferential positions of adjustfment of the supports 6 is also of material advantage in this machine.

' Briefly described, the operation of the machine is as follows: Assuming that the work,

herein shown as a milling cutter, has been thereby.

secured to the index spindle 5 as shown in Fig. l and that the grinding spindle supports have been adjusted to place the grinding wheels in the proper position relative to .on the sides of the teeth of the milling cutter while the third grinding wheel operates on the periphery thereof. Ateach rotation of the drive shaft 27 the milling cutter is indexed through the desired distance by means of the indexing mechanism heretofore described. Should it be desired to shorten the stroke of the spindles, the operator adjusts screw 36 inwardly against the arm 35 on the rock shaft whereby the rack 22 is prevented from moving its full stroke upwardly and the stroke of the spindles is shortened hat I claim is:

1. A cutter grinding machine comprising the combination of a rotary work support, a plurality of rotatable spindles each adapted to receive a grinding wheel thereon to dress the work, a support for each spindle, means permitting adjustment of each spindle support angularly relative to the work support, a member pivoted to each spindle support and having an arm directly engaging the spindle, and mechanism for operating each member about its pivot to longitudinally reciprocate the spindles.

2. A cutter grinding machine comprising the combination of a bed plate, a rotary work support thereon, a plurality of rotatable spindles each adapted to receive a grinding wheel thereon to dress the work, a support for each spindle, meanspermitting adjustmentof the spindle supports circumferentially around the bed plate, a member pivoted to each spindle support and having an arm directly engaging the spindle, and mechanism for operating each member about its pivot to longitudinally reciprocate the spindles. I

A cutter grinding machine comprising the combination'of a rotary work support,

a plurality of rotatable spindles each adapt:

7 support and having an arm directly engaging the spindle, mechanism for operating each member about its pivot to'longitudinally reciprocate the spindles, and means for automatically indexing the work support in timed relation to the spindle reciprocations.

4. A cutter grinding machine comprising the combination of a bed plate, a rotary work support thereon, a rotatable spindle adapted to receive a grinding wheel thereon to dress the work, a support for the spindle adjustable circumferentially 011 the bed plate, a member pivoted to the spindle support and having an arm directly engaglng the spindle, and mechanism including a oncularrack connected withthe pivoted memher for operating the member about its pivot to longitudinally reciprocate the spindle.

5. A cutter grinding machine comprising the combination of a rotary work support, rotatable spindles adapted to receive grinding wheels thereon to dress the work upon its sides and periphery, pivoted means directly engaging each spindle, and mechanism for operating each of the said means about its pivot to-reciprocate the spindles longitudinally.

6. A cutter grinding machine comprising the combination of a rotary work support, rotatable spindles adapted to receive grinding wheels thereon to dress the work upon its sides and periphery, pivoted means directly engaging each spindle, certain of said means being pivoted to the spindle supports, and mechanism for operating each of the said means about its pivot to reciprocate the spindles longitudinally.

7. .A cutter grinding machine comprising the combination of a rotary work support, a rotatable spindle adapted to receive agrinding wheel thereonto dress the work, a drive shaft, a member operataively connected to and adapted to be reciprocated by the drive shaft, and pivoted means forming a direct operative engagement between the reciproeating member and the spindle whereby the spindle is reciprocated.

8. A cutter grinding machine comprising the combination of a rotary work support, a rotatable spindle adapted to receive a grinding wheel thereon to dress the work, a drive shaft, a circular rack operatively connected to and adapted to be reoiprocated by the drive shaft, and pivoted means forming a direct operative engagement between the rack and the spindle whereby the spindle is reciprocated.

9. A cutter grinding machine comprising the combination of a rotary work support,

a rotatable spindle adapted to receive a grinding wheel thereon to dress the work, a drive shaft, a rack reciprocated thereby, two arms adapted to rock on a common pivot, one of said arms engaging the rack, and oscillating means forming a direct operative engagement between the other arm and the spindle whereby the reciprocation of the rack is transmitted to reciprocate the spindle longitudinally.

10. A cutter grinding machine comprising the combination of a rotary work support, a rotatable spindle adapted to receive a grinding wheel thereon to dress the work, a drive shaft, rack reciprocated thereby, two arms adapted to rock on a common pivot, one of said arms engaging the rack, a pivoted member, two arms extending from each pivoted member, one of said arms operatively engaging the spindle, and the other arm thereof operatively engaging the second arm on the common pivot whereby the reciprocation of the rack is transmitted to reciprocate the spindle longitudinally.

11. A cutter grinding machine comprising the combination of a rotary work support, an adjustably mounted rotatable spindle adapted to receive a grinding wheel thereon to dress the work, a member pivoted to the spindle support, an arm operatively connected to the spindle and movably mounted on and carried by the member, and mechanism for operating the member about its pivot to reciprocate the spindle longitudinally.

12. A cutter grinding machine comprising the combination of a rotary work support, an adjustably mounted rotatable spindle adapted to receive a grinding wheel thereon to dress the work, a member pivoted to the spindle support. an arm operatively connected to the spindle and movably mounted on the member, and mechanism including an oscillatable lever operatively connected to the member for operating the member about its pivot to reciprocate the spindle longitudinally.

13. A cutter grinding machine comprising the combination of a rotary work support,.an adjustably mounted rotatable spindle adapted to receive a grinding wheel thereon to dress the work, a member pivoted to the spindle support, an arm operatively connected to the spindle and movably mounted on the member, mechanism including an oscillatable lever operatively connected to the member for operating the member about its pivot to reciprocate the spindle longitudinally, a drive shaft, and

means reciprocated thereby and operatively connected to the lever.

14. A cutter grinding machine comprising the combination of a rotary worksupport, an adjustably mounted spindle adapted to receive a grinding wheel thereon to dress the work, a member pivoted to the spindle support, an arm operatively connected to the spindle and movably mounted on. the member, mechanism including an oscillatable lever operatively connected to the member for operating the member about its pivot to reciprocate the spindle longitudinally, a drive shaft, and a circular rack having toothed engagement with the oscillatable lever and adapted to be reciprocated by the drive shaft.

15. A cutter grinding machine comprising the combination of a bed plate, a rotary .Wheel thereon to dress the work, a drive shaft, a circular rack having the teeth thereon extending circumferentially thereabout operatively connected to andadapted to be reciprocated by the drive shaft, and means, including an element having a plurality of teeth thereon engaging the teeth on the rack, operatively connecting the spindle with the rack. whereby the spindle is reciprocated.

16; A cutter grinding machine compriswork support thereon, a rotatable spindle adjustable circumferentially on the bed plate and adapted to receive a grinding wheel thereon to dress the work, a drive shaft, a circular rack having the teeth thereon extending circumferentially thereabout and adapted to be reciprocated by the drive shaft, and pivoted means, including a.

toothed sector engaging the teeth on the rack, operatively connecting the spindle with the circular rack whereby the spindle is reciprocated.

17. A cutter grinding machine comprising the combination of an adj ustably mounted rotatable spindle adapted to receive a grinding wheel thereon, mechanism for reciprocating the spindle longitudinally, including a drive shaft, a circular rack comnected thereto and adapted to be reciprocated thereby, two arms adapted to rock on a common pivot, one of said arms having a toothed sector engaging the rack, and a pivoted member, two arms thereon, one of the said arm engaging the rotatable spindle and the second arm thereon having engagement with the second arm on the common pivot whereby reciprocatory movement of the rack will be transmitted to the spindle.

18. A cutter grinding machine comprising the combination of a rotary work support, a rotatable spindle adjustable relative to the work support and adapted to receive a grinding wheel thereon to dress the work, pivoted means directly engaging each spindle? to reciprocate the spindles longitudinally, and means to vary the length of spindle stroke.

19. A cutter grinding machine comprising the combination of a rotary work support, rotatable spindles adapted to receive grinding wheels thereon to dress the work upon its sides and periphery, means composed entirely of pivoted members to simultaneously longitudinally reciprocate the spindles by movement about such pivots,

and means whereby the length of operative stroke of the spindles may be varied.

20. A cutter grinding machine comprising the combination of a rotary work support,'a rotatable spindle adapted to receive a grinding wheel thereon to dress the work, means directly engaging the spindle and pivoted to the spindle support to reciprocate the spindle longitudinally, mechanism for operating the said means about its pivot, and means whereby the length of stroke of the spindle may be varied.

21. A cutter grinding machine comprising the combination of a rotary work support, a rotatable spindle adapted to receive a grinding wheel thereon to dress the work,

- a drive shaft, a member operatively connected to and adapted to be reciprocated by the drive shaft, oscillating means forming an operative connection between the reciprocating member and the spindle whereby the spindle is reciprocated, and means including a spring housed in the reciprocated member whereby the length of operative stroke of the spindle may be varied.

22. A cutter grinding machine comprising the combination of a rotary work support, a rotatable spindle adapted to receive a grinding wheel thereon to dress the work, a drive shaft, operating means, including a" rod and spring housed on the rod by a circular rack, between the drive shaft and the spindle whereby the spindle is longitudinally reciprocated, and adjustable means operating against the normal action of the spring whereby the length of operative stroke of the spindle may be varied.

23. A cutter grinding machine comprising the combination of a rotary work support, a rotatable spindle adapted to receive a grinding wheel thereon to dress the work,

a drive shaft, a circular hollow rack recipconnection with the spindle whereby the reciprocation of the rack is transmitted to reciprocate the spindle longitudinally, and means including a spring housed in the hollow rack whereby the length of operative stroke of the spindle may be Varied.

24. A cutter grinding machine comprising the combination of a rotatable spindle adapted to receive a grinding wheel thereon, mechanism for reciprocating the spindle longitudinally including a drive shaft, a member resiliently connected to the drive shaft and adapted'to be reciprocated thereby, a pivoted element, a plurality of arms on the element, one of said arms engaging the member and a second arm on the pivoted element having operative connection with the spindle whereby reciprocation of the member will transmit longitudinal reciprocatory movement to the spindle, and an adjustable means mounted to engage one of the said arms to limit the stroke of reciprocation.

25. A cutter grinding machine comprising the combination of a rotatable spindle adapted to receive a grinding wheel thereon, mechanism for reciprocating the spindle longitudinally including a drive shaft, a rod connected thereto and adapted to be reciprocated thereby, a circular rack resiliently mounted on the rod, a pivoted element, a plurality of arms on the element, one of said arms being in toothed engagement with the rack and a second arm on the pivoted element having operative connection With the spindle whereby reciprocation of the rack will transmit longitudinal reciprocatory movement to the spindle, and an adjustable means mounted to engage one of the said arms to limit the stroke of reciprocation.

In testimony whereof, 1 hereto afiix my signature. 7

JOHN J. TEACHER. 

